BBC News reports US Secretary of State John Kerry says "hard choices" are needed if a deal over Iran's nuclear program is to be made by Tuesday's deadline. Kerry warned that the two sides were "not where we need to be on several of the most difficult issues." His Iranian counterpart said "still nothing is clear", as ministers were set to continue talks in Vienna. Six world powers and Iran extended the deadline to Tuesday, after missing an earlier self-imposed cut-off point. Speaking to reporters in the Austrian capital on Sunday, Kerry said a deal was still possible. The so-called P5+1 group - the US, UK, France, China and Russia plus Germany - wants Iran to scale back its sensitive nuclear activities to ensure that it cannot build a nuclear weapon. Iran, which wants international sanctions that have crippled its economy lifted in exchange, has always insisted that its nuclear work is peaceful. Sticking points are still reported to be how sanctions are lifted and the amount of nuclear capability Iran is allowed to keep.